Yes, LinuxCNC is the foundation for PathPilot and is open source but Tormach has no obligation to include special code for devices such as the Vista pendant. If you have the time and the skills YOU can write whatever is needed for a particular device and then adjust things as required with each update to PP. For a supported device Tormach tests everything on each PP release. You may differ but I prefer to be making parts rather than writing and updating Python code.